I am thinking I might need to ETL data from one database to another since I might need to have sites that are different, but contents data might be needed, so, after investigation, I felt two ETLs tools might be helpful.
1. Talend Open Studio
This can have free version, I might need to use this one, and the mapping process of two data sources is also in charts.
This tool, though no place seemed to have its recommendation, by chance found it which is totally free, according to site banner, it has 15 years history and over 5W downloads so far, and it has linux version and windows version, linux version is in Java, I tried.
After moving the benetl folder to /opt, and also, this version at present is based on Java11, but I have openjdk20, I am not installing other versions of jdk before I confirm my jdk version is not gonna work for the app.
The start.sh designates the java11 java_home folder, so merely copy the second line and execute "java -***from the start.sh" and successfully launched the app, then it requires postgresSql installed, which I am not having,
I might use docker to install postgres afterwards, and try this tool,
Then compare them a bit before I finish the set up of newer release of the website base.